Weather & Climate in St Martin, Guernsey
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
St Martin experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 49°F in January while summers reach 62°F in July / relatively mild seasonal variation. Annual precipitation totals 42.9 inches. The city sits at an elevation of 318 feet.
Temperature
49°F Jan (9°C)
62°F Jul (16°C)
| Annual Average | 52.2°F |
| 3% below US avg | |
| January Average | 49°F (9°C) |
| July Average | 62°F (16°C) |
Geography
| Elevation | 318 ft (97 m) |
| Area | 2.5 sq mi (6.5 km²) |
| Population Density | 0/sq mi |
| Coordinates | 49.4371°N, 2.5548°W |
| Timezone | Europe/Guernsey |
Precipitation & Snow
Air Quality
Earthquake History
81 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.2.
| Apr 30, 1990 | 5 km SE of Saint Helier, Jersey | M4.2 | 49 km | 22 km |
| Jul 11, 2014 | 23 km W of Saint Helier, Jersey | M3.9 | 33 km | 12 km |
| Jul 11, 2002 | 3 km NW of Pluduno, France | M3.8 | 100 km | 10 km |
| Feb 25, 2015 | 30 km SW of Saint Helier, Jersey | M3.7 | 50 km | 2 km |
| Aug 17, 1995 | 28 km S of Salcombe, United Kingdom | M3.6 | 108 km | 10 km |
| Jul 26, 1993 | 5 km ESE of Villedieu-les-Poêles, France | M3.5 | 123 km | 31 km |
| Apr 22, 1995 | 6 km E of Binic, France | M3.5 | 93 km | 10 km |
| Sep 17, 1994 | 33 km NE of Plouézec, France | M3.4 | 57 km | 10 km |
| Dec 7, 1998 | 0 km SE of Cherrueix, France | M3.4 | 112 km | 2 km |
| Jun 22, 1997 | 13 km SSE of Saint Helier, Jersey | M3.4 | 56 km | 10 km |
| Aug 29, 2001 | 5 km ENE of Saint-Lô, France | M3.3 | 116 km | 6 km |
| Jul 23, 2014 | France | M3.3 | 53 km | 2 km |
| Sep 22, 1991 | 5 km ENE of Neulliac, France | M3.3 | 147 km | 10 km |
| Jul 14, 1998 | 7 km NNE of Poullaouen, France | M3.2 | 138 km | 2 km |
| Oct 16, 1997 | 4 km ENE of Torquay, United Kingdom | M3.2 | 134 km | 10 km |
| Feb 12, 1990 | 1 km N of Lanmeur, France | M3.2 | 121 km | 10 km |
| May 30, 2001 | 3 km SW of Quintin, France | M3.2 | 120 km | 8 km |
| Apr 28, 1998 | 3 km NE of Plouha, France | M3.1 | 86 km | 2 km |
| Apr 17, 1992 | 3 km SSE of Plounévez-Quintin, France | M3.1 | 139 km | 10 km |
| Jul 13, 2006 | 12 km N of Plounéour-Trez, France | M3.1 | 149 km | 13 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 0.4 m (1 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 2011 | PLYMOUTH, ENGLAND | Avalanche | 0.4 m | - | 122 km |
Source: NOAA/NCEI Historical Tsunami Database.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 49°F (9°C) | 4.1 in | |
| February | 43°F (6°C) | 3.2 in | Coldest |
| March | 46°F (8°C) | 2.9 in | |
| April | 48°F (9°C) | 2.1 in | |
| May | 53°F (12°C) | 2.0 in | |
| June | 58°F (14°C) | 1.9 in | |
| July | 62°F (16°C) | 1.6 in | Driest |
| August | 62°F (17°C) | 1.9 in | Warmest |
| September | 60°F (15°C) | 2.7 in | |
| October | 55°F (13°C) | 3.6 in | |
| November | 50°F (10°C) | 4.3 in | Wettest |
| December | 46°F (8°C) | 4.1 in |
St Martin has a seasonal temperature swing of 19°F / from 43°F in February to 62°F in August. Total annual precipitation is 34.4 inches, with November being the wettest month (4.3") and July the driest (1.6").